How to Customize
How can i customize the Logo and the theme. Can i get step by Step Guide for Customization please...
The logo is the easiest to customize. This can be found as a setting in System Admin > System Settings. You can upload a new logo that's roughly 400px by 100px.
The theme is more involved. We're in the process of refactoring Gibbon so the theming system is transitional at the moment, moving from an old theme system to a new system. There is not much in the way of documentation until these changes have been complete. The best place to start, if you have familiarity with HTML, would be to look in the resources/templates folder. These templates can be customized by placing an edited copy of them in a theme/Default/templates folder, which overrides the file in the core (replacing Default with the name of your theme if you have created a new one). From there, it's a matter of editing the HTML and template code to the desired result. The new themes make used of Tailwind classes for styling and Twig syntax for template.
Hope this helps get you started.